A man has been arrested on suspicion of sending racist tweets to two footballers, including PFA chairman Clarke Carlisle.
The 25-year-old was arrested in Gloucestershire on Wednesday night during an investigation into abusive messages sent to Carlisle and his Northampton Town team-mate Adebayo Akinfenwa.
Inspector Phil Kings of Northamptonshire Police said a man had been arrested on suspicion of committing a racially aggravated offence in a joint operation with Gloucestershire Police.
The man remained in police custody and would be questioned by officers, he added.
Last month Carlisle, who is an ambassador for campaign group Kick It Out, told the BBC that he found the FA's lack of concrete measures to counter racism in football "embarrassing", and last year made a television documentary about the issue in the run-up to Euro 2012.
Information from the Press Association was used in this report